Curiosity rolls out, and writes a message on Mars

The NASA Mars rover Curiosity began its mission of exploration this week and as it rolled out, it wrote the place of its birth on the Martian surface. The 4x4-sized unmanned explorer will travel a quarter of a mile (400 m) to an area where it will test its robotic arm and may use its sample-collecting drill for the first time. As it goes along, the treads on Curiosity’s six wheels spell out “JPL” (Jet Propulsion Laboratory) over and over in Morse code.

Curiosity began its drive on Tuesday when it traveled 52 feet (16 m). This was the nuclear-powered rover’s third drive since its landing on August 6th, the previous two being part of its three-week post-landing shakedown, and the longest to date. Its destination is Glenelg, an area that scientists say is the convergence of three types of terrain where it might be suitable for life to exist, and then it will head in the direction of Mount Sharp.

"We are on our way, though Glenelg is still many weeks away," said Curiosity Project Scientist John Grotzinger of the California Institute of Technology in Pasadena, California. "We plan to stop for just a day at the location we just reached, but in the next week or so we will make a longer stop."

Curiosity was built and is monitored by the Jet Propulsion Laboratory in Pasadena. The six 20-inch (50.8-cm) aluminum wheels that propel it at 1.5 inches (4 cm) per second each contain their own electric motor and gearbox. Though not built for speed, they provide enough torque to help Curiosity deal with the rough Martian terrain and their titanium spokes help to minimize any jolts.

The rover’s wheel treads are also unusual in that they spell out “JPL” in Morse code (.--- for J, .--. for P, .-.. for L), on the Martian soil. This isn’t an exercise in self-aggrandizement (so JPL keeps insisting), but acts as Curiosity’s odometer. By keeping Curiosity’s cameras trained on its tracks, mission control uses the code to measure how many times the wheels turn and from that they can calculate the distance traveled.

In addition to putting Curiosity’s robotic arm through its paces, the explorer will also use its mast camera to send back high resolution images of Mount Sharp. Matching of these images with those taken from its landing site, Bradbury Landing, will allow scientists to build 3D images that will be used to identify features, detect hazards and plan Curiosity's driving route.